5 Cheap and Effective Ways to Fill Raised Garden Beds
Raised garden beds hold lots of soil! Instead of filling them with expensive potting mixes, try using one of these materials. They’re budget-friendly alternatives that work well as substitutes; many are available in your backyard! Seasoned grower Jerad Bryant shares five cheap methods for filling raised beds.
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Raised beds are like blank canvases. You can imagine fresh tomato vines sprouting tall next to lettuce heads. Or, perhaps you envision climbing bean vines that clamber up corn stalks. To grow plants in them, first, you must fill them with a suitable planting medium.
Fresh potting soil is best for immediate planting, though some other materials are more eco-friendly and rewarding for your garden. For example, you can fill your raised beds with fall leaves instead of throwing them in trash bags! Fall leaves aren’t the only organic material you can use—wood, fleshy plant material, and kitchen scraps also work well.
After filling, most materials need time to decompose. Put plants in them too early and their roots may suffer in the light, airy, and actively decomposing mixes. You can put plants into a potting mix immediately after putting it down, but these other objects require fungi, bacteria, and critters to break them down into smaller particles.
With patience, time, and affordable organic items, you can turn empty beds into bustling gardens! Here are five cheap and effective ways to fill raised beds in the home garden.
Hügelkultur
Hügelkultur is a fancy German term for a specific method of raised bed filling. It translates to “hill” or “mound culture,” and involves making mounds out of old yard waste. You can turn any location into an absorbent, airy space for growing crops with objects like old logs, twigs, manure, grass clippings, and compost.
Hügelkultur is simple to set up and maintain. Start by putting down large chunks of wet wood on the bottom—they’ll create the structure for the other materials. Water each layer as you add it to preserve ample moisture. On top of the logs, layer smaller twigs, grass clippings, manure, and fall leaves until they reach close to the bed’s surface.
It’s time to add the final layer once the bed is nearly full. Scatter a thick blend of compost and topsoil to cover the organic materials, ensuring no holes are visible. Water well, then wait for a few months to plant. The wood logs may pull nitrogen from the soil as they decompose, creating inhospitable conditions for most crops. It’s best to start this method in the fall and plant in the spring.
You may grow some special species immediately after setting up your hügelkultur—leguminous crops like peas, beans, and sweet pea flowers fix nitrogen in the soil. They partner with bacteria to turn atmospheric nitrogen into an available form for themselves and others.
Buy Potting Soil
If you want to fill raised garden beds for cheap, skip the potting mix! The easiest option is the most expensive! Potting soil isn’t cheap, especially if you purchase high-end mixes with perlite, vermiculite, or other materials that require processing to create. Rather than buying them, go for cheap raised bed mixes! They often consist of partially decomposed organic materials that hold their structure well.
The best place to find bulk potting soil is at a plant nursery or a shop with landscaping materials. Bulk soil bins let you scoop up as much as you need. It costs less than buying pre-packaged bags of soil, as you bag it yourself and save on the manufacturing costs!
Not all mixes are good for raised beds. If you want to grow organic crops, avoid purchasing blends with synthetic or chemical fertilizers. Opt for partially decomposed types made from organic materials for the best results.
If you buy a partially decomposed mix, you’ll want to let it sit for a few weeks before planting into it. The time allows it to settle and break down so your plants perform well. As with hügelkultur, you may also plant leguminous nitrogen-fixing species like beans and peas immediately after set up.
Lasagna Layering
Lasagna layering is similar to making a hügelkultur bed, except it consists of even layers with less wood than the German gardening style. Another name for it is “sheet mulching.” It’s an ideal method for cheaply filling raised garden beds if you have lots of composting materials at your disposal.
The simplest way to make lasagna layers is with cardboard, paper waste, and mulch. Place the paper products on top of the soil, place mulch on top, and repeat as often as you’d like until you’re out of materials. This method works great for deep-rooted crops that love airy soil, like beets, radishes, and carrots.
Though simple to set up, the layers need many weeks before they break down fully and are ready for planting. Plant crops too early and their roots will struggle to penetrate the cardboard. Over time, the paper materials decompose with the mulch, creating humus-rich soil ideal for vegetables, fruits, and flowers.
Make Compost
I keep my raised beds full of compost. It’s easy to do, especially if you regularly garden and have plenty of organic waste. Plant scraps, kitchen debris, and fall leaves create nutrient-rich compost perfect for shrubs, trees, and fleshy plants. Compost functions like soil or mulch, and its dual purpose makes it indispensable in the garden.
All compost consists of two separate materials we call “greens” and “browns.” Greens are nitrogen-rich waste products like plant stems, banana peels, and manure. Browns have more carbon than nitrogen; we consider things like fall leaves, paper waste, and twigs as browns.
To create an effective pile, you’ll want to alternate every shovelful of greens for two to three shovelfuls of browns. Compost breaks down best with a proper ratio; too much browns or greens may lead to sogginess and bad smells.
After alternating browns and greens, water the pile so it’s 50% moist like a wrung-out sponge. Turn the pile every day or two with a pitchfork to ensure ample air circulation. If all goes well you’ll have usable compost in weeks or months!
Bury Organic Waste
Sometimes you don’t have the energy, time, or effort to make compost piles. If this is the case, try burying the organic waste instead! Worms, fungi, bacteria, and other microorganisms like archaea dissolve the waste deep belowground, converting it into humus-rich soil for deep-reaching plant roots.
For best results, aim to bury the waste a foot or deeper. If you place it too high rodents, mammals, or other critters will dig it up and create a mess. After burying, add soil until it reaches the top of the raised beds and plant crops on the surface. Their roots will creep over time, reaching the buried waste once it breaks down fully.
You may bury anything so long as it’s organic and readily decomposes—things like leaves, wood chips, kitchen and garden scraps, and paper waste are perfect. If rodents or other creatures frequent your yard, add a mesh barrier on the bottom of your beds to prevent them from tunneling up into the waste you buried.
This method also goes by “French intensive” or “intensive planting.” Learn more about its history in this easy-to-follow guide.
